Water-soluble unitized dose products have become popular in recent years. The compositions held within the water-soluble film must have a controlled amount of water so as not to preemptively dissolve the film. Instead of water, unitized dose compositions comprise solvents to solubilise ingredients and act as a carrier. In addition to these effects, solvents in the composition within the product or within the film, plasticise the film, making it more elastic and supple. However depending on the choice of solvent or amount thereof, the Applicants have found that the solvent can also negatively affect the film structure and integrity. The Applicants have found that solvents can plasticise the film to the extent that the film becomes limp, exhibiting a reduction in elasticity. When this happens the unit dose product has a soft and floppy appearance, which consumers perceive negatively. The Applicants have therefore sought to understand the effect of solvent, in the film or composition, on the transition of the water-soluble film from elastic to plastic, so as to more accurately formulate a composition to achieve the best elasticity and least plasticity.